Fast and Furious: Turning Performance

Courtesy of General Dynamics Land Systems

Viewed with night-vision technology, an eight-wheeled Stryker vehicle from General Dynamics Land Systems performs maneuvers.

Manufacturers large and small develop strategies to quickly redesign and machine new parts for military customers.

The art and science of war is always changing. In recent years, massive, carefully planned troop engagements have been replaced with small but intense clashes with insurgents wielding simple and improvised weapons at close quarters. As a result, the U.S. military is reorganizing some of its assets into agile, quick-response groups primed for fighting on multiple fronts.

New and modified vehicles and equipment are required to meet the new challenges, and political and budgetary issues are also an issue. Therefore, manufacturers of parts for the military must maximize their responsiveness and innovation.

“Fast reaction on the engineering front is absolutely essential, because the bad guys are changing their tactics and methods and we need to respond,” said Sonya Sepahban, senior vice president, engineering, development and technology for General Dynamics Land Systems, Sterling Heights, Mich., the U.S. defense industry’s largest military vehicle supplier. Editor’s note: View a video about GDLS’ “fast response” engineering in the HTML version of this article at www.ctemag.com.

Sepahban said GDLS’ continuous improvement efforts focus on speed, agility and responsiveness to ever-changing threats. An example was an effort that began in 2009, as the U.S. moved deeper into Afghanistan with GDLS’ Stryker vehicle. The eight-wheeled, 20-ton light-armored vehicle is a key element in fast-strike ground strategies. It can travel up to 60 mph and 300 miles on a tank of fuel, and has various configurations.

In late 2009, it became apparent that the flat-bottomed vehicles were vulnerable to improvised explosive devices increasingly used by insurgents. “We were seeing threats that were significantly beyond what the vehicle was designed for, and in a very short period of time we needed to have a vehicle that was significantly more survivable,” Sepahban said.

In December 2009, GDLS initiated R&D on vehicle changes to improve survivability. The goal was to supply new versions of the vehicles by June 2011, when a Stryker brigade was scheduled to rotate into Afghanistan. To speed the project, GDLS self-funded early research. “We didn’t get a contract for development until April 2010; from December to April we were working on our own because we had to meet the deployment schedule. Otherwise, the next opportunity was another year or two off,” Sepahban said.

For the redesigned Stryker, GDLS fundamentally changed the underbelly of the vehicle to a double-V design. The V shapes deflect the force of a blast; two parallel Vs maximize ground clearance, compared to a single-V hull.

By January 2011, 9 months after the contract was awarded, production vehicles rolled off the GDLS assembly line. The vehicles went into the field in May 2011, a month ahead of schedule and, as of September, GLDS had delivered 200 vehicles, according to Sepahban. Industry experts estimate that the project would have taken 3 to 4 years had it gone through the traditional design and development process.

Courtesy of General Dynamics Land Systems

A Stryker vehicle maneuvers in a war zone.

USA Today reported that in the nearly 2 years prior to the arrival of the redesigned vehicles, the Fifth Stryker Combat Brigade lost 37 soldiers and 239 were wounded. Since the redesigned Strykers arrived, that brigade has not lost a single solider. “That proves the point about how important it is to be agile and responsive,” Sepahban said.

According to Sepahban, GDLS has long maintained a culture of rapid response to customer needs. Recently, the company has bolstered those capabilities with a process for cooperation and communication that it carries out in a facility called the Maneuver Collaboration Center, or mc2 (see sidebar on page 44).

Flexible Manufacturing

To complement rapid engineering response to the changing demands of the military, manufacturers are finding ways to increase the flexibility of production operations. One of those companies is Oshkosh (Wis.) Corp., which manufactures specialty trucks and truck bodies for customers in the defense and other industries. Its vehicles for defense applications haul tanks, missile systems, ammunition, fuel, troops and cargo.

Oshkosh employs a flexible, integrated manufacturing system that enables immediate updates for its full range of vehicles. The vehicles are assembled on a LOW-TOW towline system installed by SI Systems Inc., Easton, Pa. The system is a below-floor-level conveyor that pulls the vehicles through a series of workstations. Originally installed in 1982, the system has been expanded and modified several times, not only to expand capacity but also to handle a broader mix of military and large commercial vehicles.

Courtesy of SI Systems

A nearly 2,000 ‘-long LOW-TOW towline system from SI Systems helps Oshkosh Corp. streamline production of military and other large vehicles. The trucks move through 50 workstations, where changes can be made even on a last-minute basis.

SI Systems originally installed a 1,932 ‘-long final assembly line that moves at a speed of 9 ipm through 50 workstations. Each vehicle is transported from the start of the assembly process until completion on two dollies that support the front and rear axles. According to SI, the efficiency of the final assembly line prompted Osh-kosh to later purchase additional towline systems for axle frame assembly and engine/transmission assembly.

“When SI installed the initial towline assembly system, Oshkosh was only building commercial vehicles that had a maximum completed weight of 35,000 lbs.,” said SI Systems President Bill Casey. “As their business changed, new, heavier vehicles were introduced, and military vehicles with armor plate were added to the mix. Today, these vehicles can reach final assembly weights of nearly 100,000 lbs. each. We’ve worked closely with Oshkosh over the years to design and build more robust conveyor components to handle these heavier weights and found ways to cut our delivery lead time in half.”

Oshkosh developed a proprietary manufacturing management system to complement the towline arrangement. Called ShopTech, the system delivers real-time parts lists, work instructions and engineering drawings to each workstation. Using controls, touch screens and bar code scanners, assembly personnel can access more than 160,000 engineering assembly drawings for all the vehicles Osh-kosh offers.

QC photos obtained from 10 different inspection points are delivered to all stations, allowing for immediate quality feedback and corrective action. The system is capable of implementing even last-minute changes, including introduction of new models, model variants, engine substitutions, shifts in production volumes, and model discontinuations and restarts.

Small Arms Response

In the same manner that battlefield conditions prompt upgrades in military vehicles, weapons systems manufacturing is also affected by the changing demands of combat. Chuck Fluharty, president of Apex CNC Swiss Inc., Atlasburg, Pa., said he has had to expedite machining components for small arms. For example, the shop produces a small-arms 303 stainless steel screw part that requires slotting and threading. Part production runs 61 consecutive hours unattended to create 2,750 total pieces with a ±0.0006 ” tolerance. Apex makes the parts on a Hardinge ST225 (25mm capacity) CNC Swiss-style machine.

Courtesy of Apex CNC

Apex CNC Swiss President Chuck Fluharty in his company’s shop, where small arms parts are produced, including 0.251 “-long 303 stainless steel screws (below).

Courtesy of B. Kennedy

Another part, an 11.635 “-long × 0.750 “-dia. 4140 steel small-arms component, involves threading, slotting, milling and turning in one setup. “Low-cost, quick turnaround is what will help manufacturers grow by supplying the new budget-constrained military and their vendors,” Fluharty said.

Weapon components are also subject to ongoing modifications. “Right now weight is the biggest issue on any of the squad unit-type weaponry,” he said. “We have been involved in some of the weight issues.” That included changing the workpiece material for one component from 4140 steel to titanium, which the shop regularly machines. The key consideration for titanium machining is employing upsharp tooling and modifying speeds and feeds to handle the machinablity of titanium, he noted.

In addition, the shop recently began to machine magnesium versions of a night-vision scope that previously was made from aluminum.

Courtesy of B. Kennedy

Machining of this 11.635 “-long × 0.750 “-dia. 4140 steel small-arms component involved threading, slotting, milling and turning in one setup at Apex CNC Swiss. In the interest of lightening the load of soldiers in the field, the shop later machined the part from titanium.

Similar to general manufacturing, tight budgets are forcing the military and its contractors to reexamine inventory policies. Apex was recently asked to bid on machining a tiny firing pin that typically would have been produced by a supplier making a million of them per year. “The customer asked us to bid on quantities of 100,000 and 200,000,” Fluharty said. “That is an indication they can’t just do business the way they used to by ordering large quantities and sticking them in the warehouse.”

A manufacturer that was making the parts profitably a million at a time may not be competitive at 100,000. “If they were relying on these high-volume jobs for cash flow, and they are not in a position to be more competitive with lower quantities, that puts them in a bind,” Fluharty said.

Digital Thread

Consolidating and standardizing the flow of manufacturing data also contributes to manufacturing responsiveness. Fluharty said defense industry customers are adopting a “digital thread” approach to handling manufacturing information. In a digital thread, engineering, manufacturing, QC, assembly and modification details are linked by a two-way flow, or thread, of digital data. The thread enables precise process control and can facilitate upgrades to existing components because data is always available.